TERRITORY: HYDROGRAPHY

This mosaic of physical regions, well defined structurally and morphologically, acquires a more precise identification considering the hydrography. The French hydrographic network is in fact remarkably articulated. There are four main river basins: three of them, those of the Seine, the Loire and the Garonne, largely comprise the France of the ancient reliefs, facing the Atlantic (also including the English Channel); one, that of the Rhone, develops between the Alps and the Massif Central tributing to the Mediterranean Sea. The other rivers have smaller basins and a limited regional dimension. The Atlantic rivers flow in the hilly and flat areas that largely form the French territory and their basins are divided, at least beyond a certain line, by weak watershed thresholds, which allow them to be connected by channels. Linked to each other are in particular the Loire and the Seine, which in turn is well connected to the hydrographic networks of the Meuse and the Rhine. These connection possibilities give the French hydrographic network a fundamental importance from the geographical point of view, favored in this way, the effects of navigability (which involves more than 6000 km of frequently used inland routes), the mature profile of the rivers and their regime almost constant in relation to the oceanic climate of their basins. The Loire and the Garonne arise from the Massif Central, a veritable château d’eaux which partly feeds the Rhone. But this draws most of its waters from the Alpine region and therefore has a nival regime, partly attenuated by the regulatory function of Lake Geneva. A tributary of the Rhone is, as mentioned, the Saone, which flows in the northernmost section of the Rhône furrow and which today is artificially connected to the Meuse and the Rhine, thus constituting a fundamental element in the French inland navigation network.

TERRITORY: CLIMATE

From the climatic point of view, France is largely part of the European area subject to “western” Atlantic influences; to the S of the Massif Central and on the southern side of the Alps, the country is subject to the Mediterranean climate. The oceanicity of the French climate is not the same over the whole area hit by the western winds; although the territory is entirely open to the NW, the influences are loosened towards the interior, so we can speak of a sub-Atlantic climate for the central area, which includes among other things the Paris Basin, and which is characterized by a greater continentality and a generally less humid and rainy climate. In the Alpine region, as in the Pyrenees and in the Massif Central, the altitude determines notable climatic differentiations, but in general it can be said that the slopes of the three major French mountains are well exposed to the humid contributions of the NW. In the Atlantic and sub-Atlantic climate areas, an average of 1000 mm of rain falls annually, distributed with a certain regularity over the year, although there are significant variations from the coastal strip to the interior (respectively there is an average of rainy days of 200 and 150); the amount of precipitation also varies considerably, ranging from 1500 mm along the coast to a minimum of 600 mm in the Paris Basin. According to itypeusa, precipitation increases on the Pyrenean, Alpine and Massif Central mountain slopes, registering 2000 mm per year over 1500 m. Regime and quantity of precipitation change decisively passing to the Mediterranean area, where there are drought summers and rainy winters; and quantitatively the annual rainfall is just over 500 mm (in Marseille 560 mm). From a thermal point of view we can generally speak of a cool climate, free of excesses, of consistent seasonal and daily temperature variations, although also from this point of view there are significant differences passing from the Atlantic coastal areas to the inland ones: in Paris from 5 ° C in January rises to 18-20 ° C in July, with a few days of frost. In and quantitatively the annual rainfall is just over 500 mm (in Marseille 560 mm). From a thermal point of view we can generally speak of a cool climate, free of excesses, of consistent seasonal and daily temperature variations, although also from this point of view there are significant differences passing from the Atlantic coastal areas to the inland ones: in Paris from 5 ° C in January rises to 18-20 ° C in July, with a few days of frost. In and quantitatively the annual rainfall is just over 500 mm (in Marseille 560 mm). From a thermal point of view we can generally speak of a cool climate, free of excesses, of consistent seasonal and daily temperature variations, although also from this point of view there are significant differences passing from the Atlantic coastal areas to the inland ones: in Paris from 5 ° C in January rises to 18-20 ° C in July, with a few days of frost. In Midi, sunny, there are hot summers (in Marseille the averages in July are around 24 ° C) and winters softened by the Mediterranean winds (9.8 ° C).